Internet access is becoming ubiquitous and the means by which the access is obtained varies widely. For example, the internet access may be through a Digital Subscriber Line (DSL), a cable modem, a fiber optic network, a wireless communication network, etc. When the internet service offers high data rates it is often referred to as broadband internet service. Broadband internet service is generally understood to be a service that is always on and offers data rates in the order of mega-bits per second for both download and upload.
A client device as defined in the present disclosure is a device that may access the internet from one or more of the sources from which the internet service may be available. Such client devices may include conventional devices such as a smartphone, a tablet, a feature-phone, a laptop or a desktop personal computer, etc. Other client devices may include devices that are embedded within devices that perform other functions such as an entertainment system in a home or in an automobile, a home appliance such as a refrigerator or washer/dryer, a wristwatch with a heart rate monitor, a medical device such as a blood pressure meter or insulin sensor, a utility meter, a gaming console, a camera, a navigation device, industrial equipment, etc. These types of devices are collectively referred to herein as machine type client devices.
These diverse types of client devices may access the internet service directly through one of the sources of primary internet access mentioned earlier. Alternatively, the client devices may access the internet through a local network that performs distribution of the primary internet access to the users localized in a given area. Examples of such local networks include Local Area Network (LAN) using Ethernet, Wireless LAN (WLAN) commonly known as Wi-Fi, Bluetooth™, or some other local area networking schemes. Such short range wireless networks are referred herein as Short Range Wireless Links (SRWL). When a client device is in the proximity of a location where such a LAN or WLAN access is available, it may access the internet using the LAN or WLAN. FIG. 1 illustrates an example scenario of client devices accessing internet over a WLAN network, which is connected to a traditional wire-line internet service such as DSL or cable modem. The local area where WLAN service is available is often referred to as Hotspot. The device that offers the WLAN service in a given local area is referred to as an Access Point (AP). In the present disclosure, the terms Hotspot AP or Hotspot are used interchangeably to refer the device that offers the WLAN service in a given local area.
A Hotspot AP may be connected to DSL or cable modem through any of the standardized interfaces such as Universal Serial Bus (USB), Ethernet, or proprietary interfaces. In some cases, the DSL or cable modem and the Hotspot AP may be part of a single physical device. In such cases the interface between the DSL or cable modem and AP may use Secure Digital Input Output (SDIO) or other suitable interface.
Client devices may also obtain internet access over mobile wireless networks. These mobile wireless networks are often referred to as Wireless Wide Area Network (WWAN). The internet service offered by such networks is often referred to as mobile broadband internet or Mobile Broadband (MB) and the mobile wireless networks are often referred to as mobile broadband networks. The terms WWAN and MB are used interchangeably herein.
As the variety of client devices has increased and the demand for MB access has increased, a device known as a mobile Hotspot is commonly used. A mobile Hotspot device includes both a modem for MB access and a WLAN AP (Hotspot AP) to distribute the internet to local client devices. FIG. 2 illustrates the block diagram of an example mobile Hotspot device. As shown in FIG. 2, for the chosen example, the MB modem and the Hotspot AP may be connected to each other via one of the standard interfaces used in the industry such as USB, SDIO, or proprietary interfaces. In another mobile Hotspot example, the MB modem and the WLAN AP may be a single Integrated Circuit (IC) as shown in FIG. 3.
Some mobile Hotspot devices may serve as a single function device, i.e., they only perform the mobile Hotspot function. Such mobile Hotspots may take many different form factors such as a mobile Hotspot integrated into an automobile, a standalone device that can be carried around with or without a battery, integrated into an accessory device for a tablet, a standalone device that can be powered by a wall outlet, etc.
Some client devices have multiple capabilities and being a Hotspot is one of the capabilities. For example, a smartphone may have a mobile broadband modem that may be used to get mobile internet service directly from the mobile broadband network as illustrated in FIG. 4. The flow of data is as shown in FIG. 4 from the mobile broadband modem to the application processor that processes the download and upload data and interacts with the user via the display and other elements of the user interface such as audio, vibration, etc. The smartphone may also have a WLAN modem to access internet service over a Hotspot AP. When it is in the vicinity of a Hotspot AP, it may use internet service from the Hotspot as illustrated in FIG. 1. In another smartphone example, the mobile broadband modem, the WLAN AP and the Application Processor may be integrated into a single Integrated Circuit (IC) as shown in FIG. 5.
A smartphone may also serve as a mobile Hotspot to provide internet service over WLAN to other client devices in its vicinity. FIG. 6 illustrates an example scenario where the smartphone serves as a mobile Hotspot and provides internet service to a machine type client device which may have only a WLAN access. In another smartphone mobile Hotspot example, the mobile broadband modem, the WLAN AP and the Application Processor may be integrated into a single IC as shown in FIG. 7.
A client device may use a mobile Hotspot, a Hotspot, or a mobile broadband network when internet access is required. An example of a mobile broadband network is the Long Term Evolution (LTE) from the 3rd Generation Partnership Project (3GPP). The LTE technology and its evolution are often referred to as fourth generation (4G) technologies. A client device may also use any of the previous generation technologies such as “2G”, “3G” from 3GPP and other standardization bodies. A client device may also use future generation technologies for Hotspot, mobile Hotspot, and mobile networks. Different sources of internet are generically referred to as networks herein.
Although a Hotspot or mobile Hotspot may be able to obtain internet service and distribute it to multiple client devices in a given local area, it may not be able to provide other key services that users commonly use. For example, voice calls and SMS based text messaging remain two of the most commonly used applications in client devices. A client device accessing the internet through a Hotspot or mobile Hotspot may still be receiving voice calls or SMS based text messages directly through the WWAN as illustrated in FIG. 8. Four interconnected networks are shown in FIG. 8: Public Switch Telephone Network (PSTN) 802, WWAN 804, internet 806, and WLAN (Hotspot) 808. The PSTN is connected to the WWAN through the interface 820 and to the internet through the interface 822. The WWAN and internet are connected through the interface 818. The Cable modem 812 is connected to the internet through the interface 824. These interfaces may use open industry standards or may use proprietary standards. The Hotspot, in the present example, is connected to the internet using a Cable modem interface. In the present example, the Smartphone 813 is connected to the Hotspot Access Point 810 for internet service through the Cable modem 812. Simultaneously, it is also connected to the WWAN 804 for voice calls and SMS based text messaging. The Smartphone 813 may exchange SMS based text messages with the Smartphone 814 over the WWAN 804. The Smartphone 813 may have voice calls with the landline phone 816 through WWAN 804 and PSTN 802. The cordless phone 826 may access the conventional landline voice service through the cordless base 828 which in turn is connected to the PSTN 802 though the conventional landline interface 830. The coverage area 808 of the WLAN Hotspot and the coverage area 832 of the cordless base 832 may partially or fully overlap.
The Voice over Internet Protocol (VoIP) is a protocol commonly used to provide voice, video, and other streaming services over internet. In addition to VoIP, a comprehensive set of protocols and frameworks such as Session Initiation Protocol (SIP) and Internet Protocol Multimedia System (IMS) are used to provide Rich Communication Services (RCS) over internet. Although many so called “over-the-top” applications and services such as Skype™ are available to use for voice calls and text messaging over the internet service provided by a Hotspot or a mobile Hotspot, they are limited by the number of users who have the same applications and are online at any given time. Therefore, a more comprehensive solution using SIP and its related technologies are more broadly adopted by WWAN operators.
There may be Hotspot or mobile Hotspot devices that enable all the services for a client device including voice and video calls, SMS based text messaging, and internet to be provided by a single local device. For example, a network architecture as described in MBIT 3.0-080I, incorporated by reference herein, which includes a network element, referred to herein as Base Mobile Device (BMD) 910 as illustrated in FIG. 9, may be used. The BMD 910 may comprise a modem such as DSL modem to connect with the Internet through the link 930. The BMD 910 may comprise a modem for a WWAN. The BMD 910 may perform authentication and registration with the WWAN to be able to access all the services available from the wireless network. The BMD may also comprise a modem for one of the SRWL such as WLAN. For example, the BMD may act as an Access Point for providing internet service over SRWL to the client devices that may be present in its coverage area 908. A client device that is able to connect and get internet service from the BMD is referred to herein as Group Member Device (GMD). For example, the Smartphones 912, 914 and 916 and the laptop 917 are the GMD's. The BMD may connect with the GMD's through the SRWL such as WLAN. The BMD may also connect with the GMD's through the wired connection such as Ethernet LAN 909. Example use cases of GMD's may be some or all the client devices in a home, some or all the client devices in a small office, or some or all the client devices in a mobile vehicle, etc. The BMD may provide all the services to GMDs (client devices) including voice and video calls, SMS based text messaging, and internet.
Typically, as shown in FIG. 10, a WWAN comprises elements such as client devices or mobile stations and one or more base stations. Other network devices may also be employed, such as a mobile switching center (not shown). As illustrated in FIG. 10, the communication path from the base station (BS) to the client device or mobile station (MS) is referred to herein as a downlink (DL) direction or downlink channel. The communication path from the client device to the base station is referred to herein as an uplink (UL) direction or uplink channel. In some wireless communication systems, the MS communicates with the BS in both the DL and UL directions. For instance, such communication is carried out in cellular telephone systems. In other wireless communication systems, the client device communicates with the base stations in only one direction, usually the DL. Such DL communication may occur in applications such as paging. Typically in a wireless communication system, the client device and the base station may transmit information in blocks of data and such a block of data is referred to herein as a “message.”
A base station to which the client device may be downlink synchronized and/or communicating with at any given time is referred herein as the Serving Base Station (SBS). In some wireless communication systems the serving base station may be referred to as the serving cell. The base stations that are in the vicinity of the serving base station are called Neighbor Base Stations (NBS). Similarly, in some wireless communication systems a neighbor base station may be referred to as a neighbor cell.
A client device, after initially synchronizing with a cell, may switch to another cell depending on the signal conditions, network congestion, and other criteria. The process of switching from one cell to another cell by a client device is often referred to as handover (HO) or cell reselection. In some wireless communication systems handover is also referred to as handoff. Also in some wireless communication systems cell reselection is also referred to as idle mode handoff. An NBS, to which a client device may be switching over its communication from the current SBS, is herein referred to as Target Base Station (TBS). In some wireless communication systems, a target base station is normally referred to as a target cell. Sometimes, during a handover, the serving cell and the target cell may be the same and only the channel used for communication may be changed. Such a handover, in which the cell is not changed, is called an intra-cell handover. The purpose of intra-cell handover may be that the new channel is better suited for communication than the previous channel within the same cell. Cell reselections or handovers amongst cells that use the same frequency are referred herein as intra-frequency cell reselection or handover. Cell reselections or handovers amongst cells that use different frequencies are referred herein as inter-frequency cell reselection or handover. A network may use different Radio Access Technologies (RATs) for providing various services. In a particular network, the cells of different RAT types may be overlapping or adjacent to each other. If a neighbor cell is using a RAT type that is different from the RAT type used by the serving cell, it is referred to as an inter-RAT neighbor cell.
The decision making process for handovers and cell reselections varies from one wireless communication system to another. However, the decisions are generally based on the signal conditions measurements by the client devices and reporting of those measurements to the wireless communication network by the client devices. The wireless communication network generally may influence and control the measurements and reporting process of the client device by providing parameters for the measurement and reporting process. The actual decision to perform handover may be made either by the wireless communication network or by the client device depending on the type of particular wireless communication system. On the other hand the cell reselection decisions in idle mode (i.e., when client device is not in active communication with the wireless communication network) may be generally performed autonomously by the client device. Both handovers and cell reselections may normally lead to change of cell from which the client device may access communication services. The difference between the handover procedure and cell reselection procedure depends generally on whether a client device is engaged in an active communication with the wireless communication network. In idle mode, a client device may periodically wake up to, for example receive paging messages and go to sleep by powering off most of its hardware for remainder of the duration to reduce power consumption. This is often referred to as Discontinuous Reception (DRX).
Normally, certain types of system information may be required by all client devices so that they may communicate with the wireless communication network. The system information typically includes system synchronization information, system parameters, resource allocation information, paging information, etc. The wireless communication network may transmit such system information as broadcast data so that all client devices within its coverage area may be able to receive. Such information is herein referred to as “broadcast messages.”
Similar to some client devices, a Hotspot, mobile Hotspot or BMD may also be battery operated device. For battery operated Hotspot, mobile Hotspot or BMD devices, their power consumption may be an important consideration. Power consumption may also be a consideration for non-battery operated Hotspot, mobile Hotspot or BMD devices because they may normally continuously transmit broadcast information. Although a Hotspot, mobile Hotspot, or a BMD may serve one or more client devices, often there may not be a single client device requesting or using the service. Under such conditions, it may be desirable to reduce the power consumption of the Hotspot, mobile Hotspot, or BMD.